The invention relates generally to water purification devices, and more particularly to a water purification device employing reverse osmosis.
Reverse osmosis is a well known process for removal of dissolved materials from water. See, for example, U.S. Pat. Nos. 3,367,504; 3,887,463; and 3,397,790. It has been proposed that reverse osmosis be used in devices for consumer use to purify tap water. For example, U.S. Pat. No. 4,218,317 describes a reverse osmosis water purifier for snap-on engagement to a faucet.
A reverse osmosis water purification device typically includes a housing containing a semipermeable membrane which permits water to pass through but is substantially impermeable to certain impurities. Reverse osmosis involves providing high pressure within the housing to force unpurified water through the membrane, while impurities are prevented from passing through.
It is desirable that the housing for such a device be capable of opening and reclosing to permit replacement of the reverse osmosis membrane, and that such replacement be relatively easily accomplished. It is also desirable that the housing be capable of containing high water pressure without leaking.